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Unformatted text preview: Gestation Length Cow 282 days ↘ Sow → 3 weeks 114 days ↗ Mare 336 days Ewe → 2-2 1/2 150 days Bird → Every day 1 day Fertilization • Usually occurs 24-36 hours after copulation in mammals and birds within 15-20 minutes of ovulation • Chicks develop completely in the egg and are independent of maternal care Placenta • Provide nutrients and vital gases • Removal of waste products • Production of hormones to maintain pregnancy • Chicks develop a placenta-like structure that provides an avenue for nutrients Parturition • Defined as giving birth • Around time of birth the hormone prolactin increases to stimulate milk synthesis • Hormone oxytocin brings about steady contractions Breeding • Artificial Insemination More genetic improvement through the use of sires...
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- Winter '09
- Luteinizing hormone, estrogen, follicle development, left ovary Birds